【摘要】 塑性变形技术可实现金属纳米材料的制备,并且可改进材料的表面性能。本研究设计一种镶嵌滚珠的摩擦头并安装在铣床上,对经1150℃等温10h、水冷处理后的高氮奥氏体不锈钢0Cr21Mn17Mo2NbN0.83(钢板、厚度8mm)进行表面机械压磨处理,利用光学显微镜、扫描电镜(SEM)、透射电镜(TEM)、XRD、显微硬度仪等研究分析了经机械压磨处理后实验钢表面层组织及硬度的变化,同时考察了奥氏体表面层的结构稳定性。结果表明:经240min、360min、480min机械压磨处理后,可获得具有纳米尺度的表面层,且表面层的组织稳定,仍为单相奥氏体。由表面至距表面700μm深度区域,晶粒尺寸呈梯度递增趋势;硬度由表面至基体逐渐减小,表面硬度较基体硬度提高1倍以上。更多还原

【Abstract】 Plastic deformation technology can be used to implement the fabrication of nano-metallic materials,also promotes metal materials′surface properties.In this paper,a friction head with the mosaic balls was installed in a milling machine,which conducted surface mechanical attrition & grinding treatment on the surface of0Cr21Mn17Mo2NbN0.83high-nitrogen austenitic stainless steel(sheet,8 mm thickness,after 1150 ℃ isothermal treatment for 10 hours and water quenching).By using optical microscopy,scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction,micro-hardness measurement,the microstructure,austenite stability and hardness of surface layer of the surface mechanical attrition & grinding treated material were examined and investigated.The experiment proved that a surface layer with nanoscale grains which still maintained the single austenitic structure was formed after 240 min,360min,480 min surface mechanical attrition &grinding treatment.Within 700μm depth from surface,the grain sizes were observed in a gradient distribution.The surface hardness of the processed 0Cr21Mn17Mo2NbN0.83 had an increment of more than 100% compared to the matrix.更多还原